• 한국지하수토양환경학회지:지하수토양환경
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• 제6권2호
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• pp.39-47
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• 2001

회분식 세척실험에서 적용된 혼합계면활성제 중 $POE_5$ + $POE_14$, SDS+$POE_5$가 endosulfan의 탈착에 효율이 우수한 것으로 나타났으며, 독성실험 결과 SDS+POE$_{5}$는 미생물의 활성을 다소 저해시키는 경향이 있어 $POE_5$ + $POE_14$ (1:1) 1%를 세척제로 선정하였다. In-Situ flushing 실험에서는 세척용액의 주입 flux가 1.5L/min/m$^2$일 때 67%의 제거효율을 얻을 수 있었으며, 보조용매로서 메탄올과 에탄올을 첨가한 경우에는 각각 75%와 81%의 제거효율을 보였다. In-situ flushing기법의 적용에 따른 농도 저감이 생물학적 분해에 미치는 영향을 알아보기 위하여, 초기 농도 13mg/kg dry soil과 3mg/kg dry soil인 토양을 생물학적으로 처리한 결과 제거 효율은 각각 86% 및 81%였으며, 2가지 토양 모두 24시간 이후에는 미생물에 의한 작용이 크지 않은 것으로 나타났다. 이것은 토양상에서 용액상으로의 물질전이 속도가 율속 단계로 작용하고 있기 때문이라 판단된다. 토양에 잔류하는 계면활성제가 생물학적 분해에 미치는 영향에 대하여 검토한 결과, 잔류하는 계면활성제에 의해 물질전이 속도가 향상되어 생분해가 지속적으로 일어났으며 초기 농도 3mg/kg dry soil인 경우 120시간이 경과한 후 89%의 제거효율을 나타내었다. 계면활성제와 보조용매가 동시에 잔류하는 경우에는 계면활성제에 대한 순응기간이 보다 길어지는 것을 알 수 있었으며, 메탄올과 에탄올의 경우 각각 84% 및 83%의 제거효율을 나타내었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제9권3호
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• pp.38-48
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• 2004

TEX농도의 지속적인 감소 및 비오염지역에 비해 오염지역에서 용존산소(DO), 질산염(NO$^{3-}$ ), 황산염(SO$_4$$^{2-}$ )농도의 뚜렷한 감소와 2가철($Fe^{2+}$)농도의 증가, 산화환원전위의 현저한 저하, pH중성 등의 지화학적 인자의 분포특성으로 미루어 보아 대상부지는 혐기성 상태에서 토착미생물에 의한 오염물질의 생분해가 이루어지고 있는 것으로 판단되며, 또한 이와 함께 투수성이 큰 현장부지의 지질학적 특성상 강우에 의한 지하수의 재유입으로 인한 희석 및 분산도 TEX농도의 감소에 부수적인 요인이 되었을 것으로 추정된다. 한편, 연구대상부지에서의 생분해능(EAC)은 9.04∼35.85 mg/L범위에 있으며, 평균 24.73 mg/L이었다. 그리고 연구대상부지에서 생분해에 가장 큰 영향을 주는 생분해과정으로는 황산염환원으로 기여도가 약 75%정도인 것으로 나타났으며, 다음으로는 질산염환원 그리고 산화철(3가철)환원의 순으로 나타났다. 연구대상부지의 생분해능(EAC)를 기초로 년간 분해할 수 있는 TEX의 양을 계산해 보면 121∼45.3kg/year이며, 이 값은 년간 TEX의 지하수 부하량의 약 80%정도에 해당하는 것이다. 현장부지에서의 계산된 전체 자연저감율은 0.0017∼0.0224day$^{-1}$(평균 0.0110day$^{-1}$)이며, 1차 생분해율은 0.0008∼0.0106day$^{-1}$(평균 0.0051day$^{-1}$)이었다. 1차 생분해율에 근거한 연구대상부지에서 TEX의 반감기는 866.25∼65.38일(2.37∼0.18 years)로 계산되었다.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.743-748
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• 1996

For the biological treatment of phenolic resin wastewater containing phenol and formaldehyde, a phenol-degrading yeast was isolated from the papermill sludge, and then identified as Candida tropicalis PW-51 according to morphological, physiological and biochemical properties. The strain was able to degrade high phenol concentrations up to 2,000mg/l within 58 hours in batch cultures. Phenol-degrading efficiency by the strain was maximum at the culture conditions of a final concentration of 9 $\times$ 10$^{6}$ cells/ml, 30$\circ$C and pH 7.0. The mean degradation rate of phenol was highest at 45.5mg/l/h in 1,000mg/l phenol from 500mg/l to 2,000mg/l phenol. Because the enzyme activity of catechol 1,2-dioxygenase increased in the course of degradation of phenol, it seems that this strain degrades phenol via the ortho-cleavage of benzene ring. The isolate C. tropicalis PW-51 could be effectively used for the biological treatment of phenolic resin wastewater.

• Membrane and Water Treatment
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• 제9권4호
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• pp.263-271
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• 2018

The objective of this work was to analyze organic matter removal, nitrification, biomass growth and membrane fouling in a submerged flat-sheet membrane bioreactor, fed with synthetic wastewater, of similar composition to the effluents generated in a fish meal industry. After biomass acclimatization with saline conditions of 12 gNaCl/L and COD/N ratio of 15 in the bioreactor, results showed that the organic matter removal was higher than 90%, for all organic loading rates (0.8, 1, 1.33 and $2gCOD/L{\cdot}d$) and nitrogen loading rates (0.053, 0.067, 0.089 and $0.133gN/L{\cdot}d$) tested during the study. However, nitrification was only carried out with the lowest OLR ($0.8gCOD/L{\cdot}d$) and NLR ($0.053gN/L{\cdot}d$). An excessive concentration of organic matter in the wastewater appears as a limiting factor to this process' operating conditions, where nitrification values of 65% were reached, including nitrogen assimilation to produce biomass. The analysis of membrane fouling showed that the bio-cake formation at the membrane surface is the most impacting mechanism responsible of this phenomenon and it was demonstrated that organic and nitrogen loading rates variations affected membrane fouling rate.

• 환경위생공학
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• 제13권2호
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• pp.88-94
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• 1998

This study was investigated the application of biofiltration using cometabolic process to remediate gaseous toluene that are highly recalcitrant to adsorption, absorption and biodegradation. The investigation was conducted using specially built steel columns packed with granular activated carbon for removal of toluene and G.A.C was also coated with Pseudomonas putida microorganisms by addition of KH$_{2}$PO$_{4}$. The biofilter unit was operated in the condition of dry and 27.5% moisture content at gas loading rate of 12.5 l/min. Gaseous toluene taken from tedlar bag was analyzed by the use of G.C. equipped with F.I.D. detector. The removal efficiency of gaseous toluene was 85% at average inlet concentration of 970 ppm during dry operating condition. For gaseous toluene, 91% removal efficient was obtained at the filter material with moisture content and 97% removal efficiency was obtained with Pseudomonas putida microorganisms at gas loading rate of 12.5 l/min.

• Journal of Microbiology
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• 제42권2호
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• pp.94-98
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• 2004

Phenanthrene is a three-ring polycyclic aromatic hydrocarbon and commonly found as a pollutant in various environments. Degradation of phenanthrene by white rot fungus Trametes versicolor 951022 and its laccase, isolated in Korea, was investigated. After 36 h of incubation, about 46％ and 65％ of 100 mg/l of phenanthrene added in shaken and static fungal cultures were removed, respectively. Phenanthrene degradation was maximal at pH 6 and the optimal temperature for phenanthrene removal was 30$^{\circ}C$. Although the removal percentage of phenanthrene was highest (76.7％) at 10 mg/1 of phenanthrene concentration, the transformation rate was maximal (0.82 mg/h) at 100 mg/L of phenanthrene concentration in the fungal culture. When the purified laccase of T. versicolor 951022 reacted with phenanthrene, phenanthrene was not transformed. The addition of redox mediator, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) or 1-hydroxybenzotriazole (HBT) to the reac-tion mixture increased oxidation of phenanthrene by laccase about 40％ and 30％, respectively.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.87-92
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• 1987

In order to evaluate the artificial skin for burn would covering materials, copoly(N. carbobenzoxy-L-Iysine-L-leucine)s were prepared by Ipolymerization of N - carbobenzoxy-L- I sine anhydride and L-leucine anhydride in homogeneous solvents using triethylamine as an initiator. The synthetic polypeptides and the oxter type polyurethane(PV)of medical grade were used as the sheet type membranes were prepared ; monolayer membrances were composed of only the polypeptides, bilayer membranes and blend membranes were controlled by composition of the polypeptides and PU. Test of the swelling degree, mechanical tensile strength, elongation, oxygen permeability, water-vapor loss and In vitro degradation treated by pretense TV of samples of artificial skin were measured by adequate methods so as to mechanical, physincal characterization and biodegradation. As a result, all the values of samples were found to be similar to desired value of skin which was nature. The Artificial skin based on polypeptides can be considered as ideal burn wound covering materials.

• 상하수도학회지
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• 제10권4호
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• pp.119-126
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• 1996

Influence factors and efficiency characteristics for treatment of wastewater containing phenol were studied with using Pseudomonas sp. B3. It took 130 hours to remove phenol, when only activated sludge of terminal disposal palnt of sewage was innoculated in batch culture, but it was required just 36 hours, when bacteria degrading phenol and activated sludge were simultaneously innoculated. If only phenol an carbon source was used, it necessary 36 hours for biodegradation of phenol, while glucose was added to medium, it took 73 hours. It was revealed as excellent effluent and SVI, when the F/M ratio, COD and phenol concentration were 53mg/l and 1.2mg/l, respectively, and optimum F/M ratio was revealed 0.31. The reactor were seriously shocked as reducing hydraulic retention time at constant phenol concentration more than increasing phenol concentration at constant hydraulic retention time, when volumetric loading rate was increased to $0.8kg\;phenol/m^3{\codt}d$ from $1.6kg\;phenol/m^3{\codt}d$. And also the effluent phenol concentration was 34mg/l after starting 12 hours of shocking and reactor was recovered as steady state after 65 hours of changing in the former test. Although the effluent phenol concentration was maximum value with 12mg/l after starting 20 hours of shocking and reactor was recovered as steady state after 54 hours of changing in the later test.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1230-1239
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• 2010

Five bacterial species, capable of degrading the recalcitrant organic compounds (ROCs) diethyleneglycol monomethylether (DGMME), 1-amino-2-propanol (APOL), 1-methyl-2-pyrrolidinone (NMP), diethyleneglycol monoethylether (DGMEE), tetraethyleneglycol (TEG), and tetrahydrothiophene 1,1-dioxide (sulfolane), were isolated from an enrichment culture. Cupriavidus sp. catabolized $93.5{\pm}1.7$ mg/l of TEG, $99.3{\pm}1.2$ mg/l of DGMME, $96.1{\pm}1.6$ mg/l of APOL, and $99.5{\pm}0.5$ mg/l of NMP in 3 days. Acineobacter sp. catabolized 100 mg/l of DGMME, $99.9{\pm}0.1$ mg/l of NMP, and 100 mg/l of DGMEE in 3 days. Pseudomonas sp.3 catabolized $95.7{\pm}1.2$ mg/l of APOL and $99.8{\pm}0.3$ mg/l of NMP. Paracoccus sp. catabolized $98.3{\pm}0.6$ mg/l of DGMME and $98.3{\pm}1.0$ mg/l of DGMEE in 3 days. A maximum $43{\pm}2.0$ mg/l of sulfolane was catabolized by Paracoccus sp. in 3 days. When a mixed culture composed of the five bacterial species was applied to real wastewater containing DGMME, APOL, NMP, DGMEE, or TEG, 92~99% of each individual ROC was catabolized within 3 days. However, at least 9 days were required for the complete mineralization of sulfolane. Bacterial community diversity, analyzed on the basis of the TGGE pattern of 16S rDNA extracted from viable cells, was found to be significantly reduced in a conventional bioreactor after 6 days of incubation. However, biodiversity was maintained after 12 days of incubation in an electrochemical bioreactor. In conclusion, the electrochemical reduction reaction enhanced the diversity of the bacterial community and actively catabolized sulfolane.

• 한국물환경학회지
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• 제26권3호
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• pp.446-453
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• 2010

This study was investigated nine nitrosamines in small tributary rivers, sewage treatment plants (STPs) and drinking water treatment plants. They are N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosodi-n-propylamine (NDPA), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitrosodi-n-butylamine (NDBA) and N-nitrosodiphenylamine (NDPHA). The nine nitrosamines were analyzed by gas chromatography mass spectrometry (GC/MS) using solid phase extraction (SPE) with a coconut charcoal cartridge. Among the nine nitrosamines, NDMA, NMEA, NDEA, NDPA NDBA and NDPHA were detected in small tributary rivers and sewage tretment plants. In small tributary rivers, NDMA, NMEA, NDEA, NDPA, NDBA and NDPHA were obtained as ND~16.4 ng/L, ND~17.7 ng/L, ND~102.4 ng/L, ND~455.4 ng/L, ND~330.1 ng/L and ND~161.0 ng/L, respectively. Also NDMA, NMEA, NDEA, NDPA and NDBA were investigated ND~821.4 ng/L, 22.5~55.4 ng/L, 53.2~588.5 ng/L, ND~56.6 ng/L and ND~527.9 ng/L in STPs, respectively. In drinking water treatment plants, NMEA and NDEA concentration were increased to as high as 38.8 ng/L after ozonation process. However nitrosamines were decreased subsequent biological activated carbon (BAC) treatment process. It was supposed that nitrosamines were formed by $O_3$ oxidation and were removed by biodegradation of BAC.